Fluid press



(kt 1.. L. S CHAFFER FLUID PRESS.

Filed July 29, 1943 2 Sheets-Sheet l lNVENTDF-i. 1. ES LIE LASZLU E31: HAP FER.

ATTDRN E.

Oct. 15, 1946. 1.. L. SCHAFFER 2,409,393

FLUID muss Filed July 29, 1943 2 Sheets-Shet 2 Inventor: ESL/E LASZLO SCHAFFER Patented Oct. 15, 1946 UNITED ATES PATENT oFnca FLUID rnnss I Leslie LaszloSchaffer, Vancouver, British Columbia, Canada Application July 29, 1943, Serial No. 496,635,

V 3 Claims.

'- Thisinvention relates to improvements in fluid presses. j An object of the present invention is the provision of a fluid press for forming and shaping laminated articles.

Another object is the provision of a fluid press particularly for forming and gluing plywood articles, such as clips; angles; fasteners; cabinet, furniture and panel moldings, shaped parts; and the like. 1

Another object isthe provision of a press for producing these articles without internal stresses, bridging, misalinement, twisting or warping, or in other words, articles which will always retain their proper shape. A further object is the provision of a press for molding thin laminations without splitting or wrinkling them during the operation. A still further object is the provision of a press which does not requireskilled operators.

Another object is the provision of apparatus for veneering preshaped parts or articles,

Yet another object is the provision of a press of the nature described of very'simple and inexpensive construction. i

With these and other objects-in view, the present invention consists essentially of a fluid press formolding laminated articles, comprising a mold of the shape of the finished articles, means for resiliently retaining a plurality of superposed the casing Ill may be mounted on brackets I l laminations of bendable material with glue therebetween around the mold, and means for firmly pressing the laminations against the surface of the mold to impart the shape ofthe latter to the laminationsas they are pressed together, as more fully described and illustrated by way of example in the following specification and the accompanyingdrawings, in which Figure 1 is a "front elevation of one form of press, l

Figure 2 is a plan view thereof, FigureB is anenlarged cross section through the press when open and ready for loading, Figure 4 is a similar view with the press closed, Figure 5 diagrammaticallyillustrates a press for applying one or more veneers to a mold or core.

, Figures 1 to 4 illustrate a double press, but it iscto be understood that this arrangement may also beused in a single press. The press consistsof two casings Ill and II connected together 7 at. theiradjacent edges by' -hinges l2. These casings are open topped and for convenience, may beformed from channel beams or half 'cylindersof the desired-length and width whichare' which retain said casing at an angle to thehorizontal. The casing ll may be closed over the casing 10 with the partition or base l3 therebetween and they may be flrmly held together by any suitable locking mechanism, such as by. means of clamps I5 hingedly mounted on one casing and fitting over blocks l6 carried by the other casing. As the apparatus between each side of the partition or base [3 and the adjacent casing is' the same, only one will be described in detail.

A mold ll of the shape of the finished article is mounted on the surface of the partition or base l3 facing the casing. This mold is of any practical shape, in this case it is V-shaped, and it may project through and beyond one or both ends of the casing as shown in Figures 1 and 2. The casing and partition form a support for a layer I'll of a suitable flexible material, such as canvas, yieldably mounted thereon. The layer which is connected to one side of the mold or to the partition adjacent the latter stretches across to the opposite side of the casing and has slots [9 for clearing the blocks 16 andclamps I5. The layer extends to suitable yielding means, such as springs 20, anchored to the bottom of the casing or at any other suitable point. If desired, rollers 2| may be provided at the outer side of the casing in order to prevent the layer from having to move around sharp corners. When the partition is in the vertical position shown in Figure 3, there is a space between the mold and the layer.

A filler 22 of wood or other suitable material is located in the casing and a cavity 23 of substantially thesame shape as the mold I1 is cut therein. The cavity is,'however, larger than the mold so that when the latter is placed inthe former, there is a space therebetween for hold: ing a bag 24 formed of a suitable fluid-impervious flexible material. The bag in this space will assume substantially the shape of the cavity and mold, and shoulders 25 on the filler extend over the upper edges of the bag. The space between these shoulders is equal approximately to the 3 width of the mold ll at the top thereof. Fluid under pressure is supplied to the bag through a pipe 26 which extends through the bottom of the casing. If desired, a protective layer 21 of canvas or the like may be placed over the top of the bag. It is obvious that, in place of the bag 24, a layer of fluid-impervious material may be secured to the inner surfaces of the shoulders 25 forming a space above the surface of the cavity into which the fluid may be directed.

The molds in this press are designed to form relatively long plywood angles and so the molds are V-shaped in section and are fairly long.

In operation, the press is opened up, as shown in Figure 3, that is, the casing II is moved about the hinges 12 away from the casing H] as far as the brackets will permit. This causes the partition l3 to assume a vertical position and the layers Hi to stretch out over the entrance to the cavity 23. A plurality'of laminations 30 of bendable material, say for example, wood, with glue therebetween, are placed on each layer IS. The laminations may or may not be encased in or covered by paper or other material. It is only necessary to move the laminations inwardly towards the mold as far as they will go. This automatically retains them in their proper positions. Then the casing II is closed over the casing it with the partition therebetween and the unit locked in this position by means of the clamps l5. This loading is a very simple operation and may be done by anyone without any special training.

The action in each section of the press is the same. During the first part of the movement, the side of the mold i1 bears against the laminations, and the mold presses the laminations into the cavity 23. Actually, the pressure is first applied to the laminations by the outermost part of the mold, and this part presses them into the cavity. In other words, the first and greatest pressure is directed along the main bending line of the laminations, resulting in intimate contact here before the fluid pressure is applied. All this time, the layer I8 firmly presses the laminations against the mold so that they cannot move out of place, and yet the yieldable support of the layer permits the laminations to move relative to each other and away from the bending line when they a are assuming their final shape during this operation. The necessity for this relative movement may be illustrated by bending a groupof pages of a book. It will be noted that if the pages are kept against each other there is a relative movement therebetween resulting in a bevel being formed at each side edge of the pages. With this V-shaped mold, the layer holds the laminations most firmly at the point where they bend around the bottom relatively sharp corner of the V. This is very desirable and it results in the laminations being pressed from this bending line towards their sides. The layer l8 supporting and guiding the laminations continuously during the whole loading and closing operation, prevents the displacement, splitting, wrinkling and overlapping of the laminations, which would happen if they were not so supported and guided continuously When the press is locked, the bag 24 (or the space beneath the layer covering the surface of the cavity) is filled with fluid under pressure. This exerts the same pressure over the entire outer surface of the laminations bent around the mold. As well known in hydraulics, the pressure is exerted at right angles to the surface at all points. Asthis pressure is applied, the yielding layer I 8, while pressing the laminations firmly at the bending line, permits relative movement of the laminations laterally away from the said line so that all the laminations are intimately 5 retained together. This method maintains the laminations in proper alinement and, consequently prevents the development of internal stresses which might later alter the shape of the finished article. It also prevents bridging which is the result of glue failure along the bending line. The fact that the pressure is first applied on the bending line and a firm contact is maintained thereon by layer 18 prevents the laminations from separating from each other at any point. The movement of the wood away from' the bending line before the main pressure is applied eliminates any possibility of this movement being stopped by the pressure along the relatively large sides of the V. It will be noted that there is very little strain on the bag at any point because it is supported on all sides by the filler 22, shoulders 25, layer lBand the laminations on the mold. The bag is emptied before the press is opened and it is preferable to have a valve in the fluid supply line, which is closed after the bag is deflated so that the latter will not materially rise in the cavity when the molded article is removed.

Cold-setting or hot-setting glue may be used. In the latter case, the mold I1 is heated in any suitable manner, such as by means of an electric heating element 3|. A thermometer and a thermostat may be provided for indicating and regulating the temperature of the mold. The bag is spaced from the heated mold, by the laminations to be bent and the flexible layer 18 and also the layer 21, if used. consequently the bag is not liable to deterioration due to overheating because it does not come into direct contact with the heated mold. In the right section of the press the cavity 23 moves towards the mold [1, while in the left section thereof, the latter moves towards the former.

While this press has beenshown with layers I8, it may be used without them. In this case, 45 the laminations would have to be placed on the filler 22 over the cavit 23. In fact, they may be premolded into approximately their final shape before gluing. The mold I1 then presses said laminations into the cavity and they are pressed 50 against the former by the pressure of the bag.

This is not considered as satisfactory as the firstdescribed method, since there is more likelihood of the laminations becoming displaced during this operation and since the relative movement of the laminations may not be sufiicient to eliminate all the disadvantages of the systems wherein no such movement and no initial pressure on the bendingline is provided for.

The layer I8 is an important element in this 60 press. The resistance it offers causes the pressure first to be, applied to the bending line as the mold moves towards the cavity. In fact, once the layer has wrapped the laminations about the mold; the final pressure may be applied to said laminations in any suitable manner; although the fluid pressure is preferred.

Figure 5 shows the press adapted for veneering wood molding or veneering'cores. In this modification the casings are indicated by the numeral 70 35 and are connected together by a hinge 36 which supports a partition or base 31. The base is adapted to receive one or more strips 38 previously referred to as cores, which are to be covered with aveneer. These cores are adapted to 75 be secured to the base by any suitable means and to be readily removable after the veneer is applied, a layer 39 of flexible material is fastened along one of its borders to the base 37 and eX- tends over the remote side edge of each casing, where it is held taut by springs as. The casings are provided with fillers 4| defining cavities 42 and each cavity is preferably fitted with an air bag M, as previously described. The springs 4i] tension the layer 39 and as the casings are closed, the layer exerts the initial pressure upon the veneer, forcing it into intimate contact with its core 38, ready for the final fluid pressure to be applied through the medium of the bag 44, infiated by steam, compressed air, or liquid.

What I claim as my invention is:

l. A fluid press for molding laminated articles, comprising two casings hingedly connected at their adjacent upper corners, a base hingedly mounted between the casings, a mold of the shape of the finished article mounted on each side of the base, a cavity in each casing adapted to receive the mold on the base opposite its casing, a layer of flexible material positioned on opposite sides of the base, each layer being connected at one of its ends to the base of each mold and extending over the entrance to the cavity, resilient means connected to the opposite end of each layer to keep it taut, each of said layers being adapted to receive between itself and the adjacent mold a plurality of superposed laminations of bendable material with glue therebetween and yieldably to press and hold against disalignment said laminations around the molding surfaces of the molds as the molds are moved into the cavities when the casings are brought together with the base therebetween, means within each cavity capable of moving outwardly therefrom, means for firmly holding the casings together, and means for moving the movable means of the cavities outwardly therefrom to press the articles against the molds.

2. A fluid press for molding laminated articles, comprising two casings hingedly connected at their adjacent upper corners, a base hingedly mounted between the casings, a mould of the shape of the finished article mounted on each side of the base, a cavity in each casing adapted to receive the mold on the base opposite its casing, a layer of flexible material positioned on opposite sides of the base, each layer being connected at one of its ends to the base of each mold and extending over the entrance to the cavity, resilient means connected to the opposite end of each layer to keep it taut, each of said layers being adapted to receive between itself and its adjacent mold a plurality of superposed laminations of bendable material with glue therebetween and yieldably to press and hold against disalignment said laminations around the molding surfaces of the molds as the latter are moved into the cavities when the casings are brought together with the base therebetween, a fluid-impervious flexible bag lying on the surface of each cavity, means for firmly holding the casings together with the molds in the cavities, and means for supplying fluid under pressure to the bag to press the articles against the molds.

3; A fluid press comprising a casing, a base hingedly mounted on the casing at one side thereof, a mold mounted on the base, a cavity in the casing adapted to receive the mold, a layer of flexible material secured at one of its ends to said base in close proximity to the mold and stretching across the cavity, resilient means anchored to a fixed point and connected to the opposite side of the layer to keep it taut, said layer being adapted to receive and hold against disalignment bendable material between itself and the mold and yieldably to press said material around the mold as the base is pivoted to move the mold into the cavity, means within the cavity capable of moving outwardly therefrom, means for firmly holding the mold in position in the cavity, and means for moving the movable means within the cavity outwardly to press the material against the mold.

LESLIE LASZLO SCHAFFER. 

